package com.gxc.linkedList;

/**
 * 给定一个二叉树, 找到该树中两个指定节点的最近公共祖先。
 */
public class LowestCommonAncestor {

    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
        if (root == null || root == p || root == q) return root;

        TreeNode left = lowestCommonAncestor(root.left, p, q);
        TreeNode right = lowestCommonAncestor(root.right, p, q);
        if (left == null) return right;
        if (right == null) return left;
        return root;
    }

}

class TreeNode {
      int val;
      TreeNode left;
      TreeNode right;
      TreeNode(int x) { val = x; }
  }
